The Treasury has clashed with Stephen Byers over his claim to have secured an additional £2.2 billion in transport spending.

Byers claimed he had secured the "additional" cash after weekend negotiations with the chancellor.

However Gordon Brown's officials insisted that the cash had been earmarked for the transport plan as long ago as last April.

The unprecented spat between two key departments was seized upon by the Tories as further evidence of Byers' mismanagement of his transport portfolio.